Annealing furnace



July l2, 1949, P. MASTERCOLE ANNEALING FURNACE Filed Feb. 3, 1947 LET INVENTom PH :MP MASTERCQLE ATTORNEY Patented July 12, 1949 .ANN EALIN G FURNACE,

Philip `lw'astercoa Steubenvillc,0hio; Mary Mastercole, exccutrixfof said Philip Mastercole, deceased, assignor to Mary Mastercole, Steubenville, Ohio .Application February 3, 1947, vSerial No. 726,135

(Cl. 26S-4,6)

1 Claim.

My invention relates to annealing furnaces of the type-described for example in the Clarence B. I-Ioak Patent No. 2,239,523, which involves the heating of annealing boxesvor the like by both radiation and convection. In the present instance, the `furnace maybe of the vportable hood type or not, as may be desired.

In the said patent, radiating Walls composed of slabs are mounted 'interiorlyfofthe furnace hood, the walls extending only partway to the furnace roof and the gas burners -entering through the side walls of the furnace, the combustion spaces or chambers being located between the radiating walls and the adjacent side walls of the furnace. A substantial or major portion of the heat is transmittedthrough the radiating wall to the annealing box or other work pieces in the furnace, some of the heated gas, however, passing over the topscf the radiating walls into the annealing chamber, so that there is heating both by radiation and convection.

The present invention has for its object the provision of a furnace structure of the character referred to wherein the radiating walls or slabs are mounted in place and connected to the side walls, in an improved manner, without the necessity of using anchoring bolts.

As shown in the accompanying drawing, Figure 1 is a vertical sectional view through a portion of an annealing furnace equipped with my invention; Fig. 2 is a view taken on the line II-II of Fig. 1; Fig. 3 is a view taken on the line III--III of Fig. 1; Fig. 4 is a view showing a modification of the structure of Fig. 1, and Fig. 5 shows still another form of the invention.

The furnace is shown as provided with the usual hearth or foundation 5 and the usual metal shell comprising plates 6 and buck stays 'I. Where the furnace is to be of a portable type, a metal bottom plate 8 will be employed as part of the metal structure.

The side walls of the furnace will be made of insulating bricks 9 which are of a porous nature, so that they can be sawed and cut to form notches as hereinafter explained.

Slabs or blocks I0 of highly refractory material such as silicon carbide serve as heat-radiating elements through which heat will be transmitted from the ames produced by the burner or in the spaces between the blocks I0 and the side wall bricks 9. Where the slabs IU are tongued and grooved on their horizontal edges as shown at Il, mortar will not be required at these horizontal joints. The slabs have grooves in their vertical edges for interlocking engagement with ribs I2 that are formed on tie blocks or plates I3 which will be of material suiiiciently refractory to withstand the high temperatures in the combustion space behind the radiating wall. These tie plates are of lT-shape at their outer vertical edges, as shown at I4 and these heads will interlock with notches in certain of the bricks 9., the said notches `seing formed therein by Lsawing or otherwise. The radiating wall slabs III .are thus held in position. The usual burners l5 fwill supply gas for combustion. There is, inf-effect, a combustion chamber oraspace foreach burner, as shown moreclearly in'Fig. 2,ahd thes'efwill be individually controlled so that .there can be an .even heating of `an annealing box orwork piece yat the various pointsthroughout thel-ength of the .furnace. This avoids overheating certain portions of the annealing box suchas ,frequently occursparticularly at amid point vin the furnace.

Furthermore, the vertical length of the burner flame in the combustion chambers can be controlled, so that there can be greater or less radiation of heat at desired levels. When the furnace is rst put into operation, gas can be supplied at a high rate to produce flames that may extend to and above the upper edges of the radiating walls. However, after initial heating has been had, the supply of gas will be reduced, and the major portion of the heat to the work will be supplied by radiation from the slabs I0.

At the vertical tongues and grooves I2, horizontal tongues and grooves I I and the 'i' connections IIS, no mortar is required, and there can be shifting of the members I2 and I3 under temperature changes, without damage to the joints.

Another advantage of the interlocking arrangement as between the slabs I0 and the tie plates I3 is that the slabs I0 can readily be replaced in case of damage, simply by lifting off as many slabs as is required to reach a slab in a particular vertical row that requires replacement, and without disturbing the slabs in the other rows or the tie plates I3.

In Fig. 4, I show an arrangement wherein tie plates I'I of somewhat different form than the plates I3 are employed. In this case, portions of the plates I'I are cut away as at I8 to provide crosswise communication between the combustion spaces. While the major flow of heated gases will be in the Vertical paths provided by the plates I'I, there will be some horizontal flow through the passageways I8. In some cases for example, the mid portion of the annealing box will be sufficiently heated at an early stage, and

complementallyshaped therefore, gas to the adjacent burners can be shut od, adequate heat to maintain the temperature at such mid portion of the box being secured by the small crosswise flow through the passageways I8. In this structure, the radiating blocks 19 are smooth along their horizontal edges instead of tongued and grooved as at I l in Fig. 1. When required, mortar will be used at these joints. The ends of the tie plates l1 will be ribbed and have connection with the radiating wall and the side walls of the furnace in the saine manner as in Fig. 2.

As to the dimensions of the small combustion chambers in front of each burner, they may suitably be about 10 inches square internal dimensions, as indicated in Fig. 2. It will be understood, of course, that the notches in the bricks 9 for the heads lll of the tie plates i3 may be set at various distances inwardly from the metal shell 6, which will change the width of the combustion chambers in that direction. This may be desired in some instances where combustion chambers of certain particular dimensions are desired. Also, there will be instances where limitations of space will require that the radiating slabs be set closer to the insulating wall bricks 9, as when this improved furnace hood is to be placed on an old foundation. In that case, the notches in the bricks 9 for the anges I4 will be cut closer to the outer ends of these bricks, and the slabs Il) of the tie plates therefore will be located closer to the bricks S.

As shown in Fig. 5, the positions of the tongues and grooves in the tie plates I3 and the radiating slabs IB may be reversed, so that the tie plates 2l have the grooves, and the radiating plates 22 can be rounded at their vertical edges to t into the grooves 23 of the tie plates.

I claim as my invention:

An annealing furnace comprising a side wall and a roof, radiating wall slabs disposed in interiorly-spaced relation to the side wall and in a plane generally parallel to the side wall, and extending to a plane spaced a substantial distance below the roof, tie elements having their outer ends held by the side wall, and interlocking surfaces along the vertical sides of the tie elements, positioned between the ends of adjam cent slabs, the slabs having complementa-ilyformed loose-fitting interlocking surfaces, along their Vertical edges, whereby the slabs may be dropped into assembled position with respect to the tie elements, the interlocking elements be ing formed of plates arranged in laterally-spaced planes that are perpendicular to the planes of the side wall and the slabs and extending from the lower edges of the radiating wall to approximately the upper edges thereof, each slab being co-extensive in height with its associated plates, and means for supplying fuel into the lower ends of the passageways formed by the slabs and plates.

PHILIP MASTERCOLE.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 1,296,122 Roth Mar. 4, 1919 1,502,070 Tone July 22, 1924 2,084,241 Capper June 15, 1937 2,255,617 Hoak Sept. 9, 1941 FOREIGN PATENTS Number Country Date 370,217 Great Britain Apr. 7, 1932 

